Questions about parallel plate size

Hi everyone, new member here and I apologize in advance if my questions seem somewhat amateur.

Recently I've started learning about capacitors, electrostatics and electric theory in general. I guess I'm having trouble trying to wrap my head around the actual area (size) of the plates of a parallel capacitor. For instance......if I want to size a capacitor that has the charge of 1kwh...(3,600,000 joules), at 50 kv, the equations say I would need a cap size around .00288 farads.

When I try to calculate the area of the plates for a .00288 cap with .5 meter separation, a dielectric permittivity of 3.....I get a plate area size of .00048 meter square.

This seems like an awfully small plate size to hold that amount of energy.

I guess I'm just looking for some validation to my answers, and if not maybe someone could point me in the right direction. Thanks for your replies in advance.

I thought this is telling me the needed capacitor size in farads if I know the amount of energy I want stored in joules (3,600,000) at 50 kv.

From there, knowing the capacitor size in farads, I wanted to calculate the actual plate size needed for a cap rated at .00288 farads.

Not using vacuum in the gap, we'd be using a silicon oil...transformer oil. Say the permittivity is 25, dielectric constant 2.7. This is rated up to 50 kv......probably wouldn't charge the cap to the max but just using it for an example :)
Thanks again.

Staff: Mentor

When Tesla needed high voltage condensers for his trans-Atlantic transmitting station, he had long barns constructed, the height of two-storey houses, and filled them with metal panels hanging vertically from the ceiling to form air-spaced condensers. The panels were kept in place with, I think, glass insulators and separators.